Bamboos are fast-growing plants, with outstanding physical-mechanical characteristics that may be chiefly ascribed to the features and dimensions of their main structural element: their fibers. This study aimed to perform a dimensional description (length, width, lumen diameter and wall thickness) and depict the indices and technical coefficients of fibers of bamboo species that occur in Brazil, through a bibliographical survey. The results showed that the basic density in test stem-specimens of the surveyed species varied between 0.451 g cm-3 and 0.780 g cm-3, what revealed a great variability among them. The average values observed for the fiber dimensions were 2.29 mm for length, 16.4 µm for total width, 6.4 µm for wall thickness and 3.5 µm for lumen diameter. From these data, it was possible to estimate indices and technical coefficients that support good physical-mechanical characteristics of bamboo in the several studied species.
Fossil fuels are being replaced by clean energy sources. Lignocellulosic biomass is considered an eco-friendly alternative, as it is a renewable raw material with high energy potential. In this context, the aim of this study was to determine the biomass energy properties of three bamboo species and mate. Thus, three species of bamboo (Bambusa vulgaris Var. Vittata, Dendrocalamus asper and Phyllostachys aurea) and Ilex paraguariensis co-products (branches and sticks) were performed. The particle size, basic density, moisture content volatiles content, ashes content, fix carbon, gross and net calorific value and energy density of these biomasses were evaluated. The biomasses analyzed here were considered suitable for energy purposes, in general, these presented volatile content between 75 and 85 %, fixed carbon content between 15 and 25% and ash content close to 1%. Average fix carbon content of all analyzed biomass was 16.13%. Ash content of Phyllostachys aurea, branches of Ilex paraguariensis and Dendrocalamus asper presented lower values, average of 1.63%. Bambusa vulgaris and Ilex paraguariensis sticks presented higher values, average of 2.65%. Phyllostachys aurea presented gross calorific value higher than, average of 19.35 MJ kg− 1. Bambusa vulgaris, Dendrocalamus asper, Ilex paraguariensis branches and sticks presented statistically equal values. Bambusa vulgaris, Dendrocalamus asper, Phyllostachys aurea showed net calorific value higher to the other analyzed materials and did not present statistical difference. Basic energy density of Phyllostachys aurea was higher to bamboo species. Ilex paraguariensis showed the lowest values with no statistical difference for branches and sticks. Article highlights: Knowledge of biomass properties enables the use of residues in bioenergy production as an eco-friendly alternative. Bamboo and Mate co-products have desirable characteristics and potential to produce bioenergy. The energetic performance of bamboo biomass was superior when compared to the branches and sticks of Ilex paraguariensis.
Bamboo is a material used on a global scale in several areas. However, it needs adaptation in the processes for industrial use, in Brazil. The production of glued laminated panels has been growing in the world and this material can be a source of resources for this purpose. This study aimed to evaluate the physical-mechanical properties of laminated bamboo panels produced with two species (Phyllostachys aurea and Dendrocalamus asper) and two production processes/adhesives (glued-laminated bamboo and thermo-mechanical laminated bamboo). For the mechanical properties analysis, specimens removed from the panels were subjected to shear tests, Janka hardness and static bending. The same specimens were used to determine the apparent density, moisture content and degree of compression. The apparent density varied between 0.75 g cm-3 and 0.79 g cm-3, with equilibrium moisture contents between 7.83 % and 10.42 %. The highest values for the mechanical properties were verified in the thermo-mechanical laminated process. For D. asper, the modulus of rupture was 146.8 MPa, the shear glued line 6.36 MPa and the Janka hardness 3,852 N, while, for P. aurea, the modulus of elasticity reached 19,603 MPa. It was concluded that the production of bamboo laminated panels, especially using the thermo-mechanical process, can be a potential alternative.
The present work aimed to evaluate the wood of fourteen genetic materials (nine species, between native and exotic, and five clones of Eucalyptus) cultivated under two post-planting irrigation regimes in the Brazilian semiarid region. For each genotype, six trees (11 years old) were selected and subjected to two initial irrigation regimes (up to 12 months and up to 36 months) after planting. Discs of different stem heights were taken: 0% (base), breast height (DBH), 20%, 40%, 60%, 80%, and 100%. Samples were extracted along the radial axis of each disk at three regions (the pith-adjacent region, intermediate region, and bark-adjacent region). Samples were subsequently saturated in water to determine their density via the water displacement method. The irrigation systems caused changes in the pattern of radial and longitudinal variation in the clones regarding the proportion of woody material in the stem. Among the native species, Angico stood out with a high density and little juvenile wood, and Pau d’arco, with a low density and a high rate of juvenile wood. Among the exotic species, Nim presented a high density and a low rate of juvenile wood, and Chichá presented a high rate of juvenile wood and a low density. In the Eucalyptus hybrids, VE38 stood out with a high density. Overall, there was an influence from irrigation management, observed with greater intensity in exotic species for Mahogany and Acacia and for the VE41 and AEC1528 clones of Eucalyptus. The values of basic densities in the trees varied from 0.35 to 0.85 g·cm−3. There was good adaptation of native and exotic species and clones to the planting area in the Semiarid region.
This study assessed the properties of particleboard produced from the replacement of urea formaldehyde with cassava starch. Cassava starch (CS) and urea-formaldehyde (UF) were mixed at percentages of 100/0, 90/10, 70/30, 50/50, and 0/100, respectively. The mixture was added to the wood particles at 15% adhesive content based on the weight of oven-dried particles. Particleboards of sizes 20 mm × 300 mm × 300 mm and a targeted density of 600 kg m–3 were manufactured by hot-pressing at 170 °C, compacting pressure 3.5 MPa for 8 min. Physical and mechanical properties (density, thickness swelling, water absorption, static bending, and hardness) were tested. The physical and mechanical properties also increased in the highest proportions of UF. Comparatively, manufactured with 50% CS + 50% UF, it performed better in all the evaluated properties. Thus, it could adopt the latter mixed ratio in the industry to reduce the quantity and cost of UF and its environmental emissions. The results obtained were adequate and in conformity with international standards. Hence, it could mix cassava starch and urea formaldehyde adhesives in different ratios to get desirable properties. It is possible to conclude that cassava starch could be considered a sustainable alternative adhesive.